Preparation and thermal properties of expanded graphite/paraffin/organic montmorillonite composite phase change material

Expanded graphite (EG)/paraffin/organic montmorillonite (OMMT) composite phase change material (PCM) was prepared by using melt intercalation method. The microstructure of EG/paraffin/OMMT is observed by scanning electron microscope (SEM). The thermal properties are investigated by differential scanning calorimetry (DSC). The mass loss of EG/paraffin/OMMT after 50 heating cycles was measured for investigating the influence of EG and OMMT on the thermal properties of paraffin. The results show that EG and OMMT have the ability of adsorption and shape-stability. The melting point EG/paraffin/OMMT is decreased slightly with an addition of paraffin and the latent heat of EG/paraffin/OMMT is determined by the mass ratio of paraffin. The heat transfer efficiency of EG/paraffin/OMMT is strengthened and the heating time is decreased to one-sixth of that of paraffin by addition of EG and OMMT. The thermal stability of EG/paraffin/OMMT is improved by addition of OMMT.